body{
    background-image: url(../../resources/image/background.jpg);
    background-repeat: no-repeat;
    background-size: 100% auto;
    display: flex;
    align-items: center; /*定义body的元素垂直居中*/
}

.button-basic{
    width: 15%;
    padding-bottom: calc(7.5% + 24px);
    padding-top: calc(7.5% - 24px);
    height: 0;
    font-size: 48px;
    font-weight: bold;
    border-color: #FFFFFF;
    border-radius: 10px;
}

.tutorialBackground{
    position: fixed;
    left: 0px;
    top: 0px;
    background: #000000;
    width: 100%;
    height: 100%;
    opacity: 0.75;
    z-index:100;
}
.pages{
    position: fixed;
    right: 0px;
    top: 10%;
    width: 50%;
    height: 80%;
    z-index:101;
}
#nextButton{
    position: absolute;
    color: #ffffff;
    right: 10%;
    bottom: 10%;
    font-size: 42px;
    font-weight: bold;
    font-family: Arial Black, Gadget, sans-serif;
    text-align: center;
}
.pageWord{
    position: absolute;
    color: #ffffff;
    right: 10%;
    top: 10%;
    font-size: 42px;
    font-family: Arial Black, Gadget, sans-serif;
    font-weight: bold;
    text-align: right;
}
#arrow {
    position: fixed;
    left: 410px;
    bottom: 120px;
    background-image: url("../../resources/image/Arrowlu.png");
    background-size: 100%, auto;
    background-repeat: no-repeat;
    width: 5%;
    height: 13%;
    z-index: 201;
}
#page4-1{
    position: fixed;
    left: 25%;
    bottom: 12%;
    font-size: 36px;
    font-family: Arial Black, Gadget, sans-serif;
    font-weight: bold;
    text-align: center;
    color: #ffffff;
    width: 50%;
    z-index:201;
}